[HydrogenBond]

At the smallest levels of nature things are quantized. But as we get larger the quantum and wave aspects of the sub-micro no longer apply. For example, the pebbles in a river bed are not quantized nor would the motion or position of any rock be explained waves or uncertainty. I am pretty certain that rock is right there. On the other hand, at the microscopic level particular minerals will show quantum structure in terms of the repeat pattern of the atoms in the unit crystal. Does quantum and all its affects breaks down at a certain level size?

The reason this is important, is say you were using quantum principles for gravity. Since two pebbles from the river bed are not quanta, a quantum analysis is not exactly correct. It works better for very small. But the implication is if there was a way draw a curve between quantum and not quantum this may provide a backdoor way to include GR into quantum mechanics. GR is more appropriate to larger mass more in the range where the quantum doesn't apply.

[Little Bang]

There is one thing that applies at every level and that is time.

[CraigD]

Originally Posted by HydrogenBond

At the smallest levels of nature things are quantized. But as we get larger the quantum and wave aspects of the sub-micro no longer apply.

I believe it’s more accurate to say, rather than “when we get larger quantum physics no longer apply”, “when we consider ensembles of great numbers of particles, it is more useful to consider them statistically than individually”.

Originally Posted by HydrogenBond

For example, the pebbles in a river bed are not quantized nor would the motion or position of any rock be explained waves or uncertainty. I am pretty certain that rock is right there.

I think the last sentence is correct – we are pretty but not completely certain the rock is right there. There is a miniscule, but non-zero, probability that the rock is not there, but over there.

Also, when you look at the rock with the naked eye, you’re not looking at it very closely. If you “look” at it very closely – for example, by placing suitable detectors around it to detect individual particle tunneling events, you’d see quantum effects.

Originally Posted by HydrogenBond

Does quantum and all its affects breaks down at a certain level size?

In short, no. Rather, the composite probabilities of individual particles being detected within volumes other than the most probable result in the probability of the average of the entire ensemble being detected other than within the most probable volume so small that that, for all the pebbles that have or will ever be observed by all people who have or will ever observe pebbles, it is almost certain never to be observed.

Originally Posted by HydrogenBond

The reason this is important, is say you were using quantum principles for gravity. …

A theory of quantum gravity is arguably the big challenge of present day physics. The challenge of writing a theoretical formalism of quantum gravity may well be less difficult than designing an experiment that can test it. Gravity is so weak compared to fundamental interactions – by a factor of or more – that repeating past successes at observing single particle interactions seems unlikely.

Not an easy problem.

[HydrogenBond]

The electron has a certain level of uncertainty. But the rock is not a simple addition of the uncertainty within all the electrons. The composite sort of cancels most, if not all that uncertain, to get something that is more certain that the sum of the parts.

.

[LaurieAG]

Originally Posted by HydrogenBond

Does quantum and all its affects breaks down at a certain level size?

The reason this is important, is say you were using quantum principles for gravity. Since two pebbles from the river bed are not quanta, a quantum analysis is not exactly correct. It works better for very small. But the implication is if there was a way draw a curve between quantum and not quantum this may provide a backdoor way to include GR into quantum mechanics. GR is more appropriate to larger mass more in the range where the quantum doesn't apply.

Hi HydrogenBond,

I've been reading Einstein '100 years of relativity', edited by Andrew Robinson, and there seems to be a couple of quotes that could lead in the general direction you are pointing.

The first one is by the editor on p93

The Heisenberg Uncertainty Principle states that the uncertainty in the position multiplied by the uncertainty in the momentum will always exceed a constant based on Plancks constant h.

I've always felt that there had to be something consistent in both the macro and the micro, related via something like a reciprocal and a constant.

The second is by Steven Weinberg on p105

In Einsteins 1915 formulation of general relativity, gravitation appears as a natural consequence of the geometry of space and time, and (aside from possible effects that would vanish at sufficiently large distances) the gravitation field equations are nearly unique.

While Steven Weinberg may not have actually said that gravity itself vanishes at sufficiently large distances, the context of the quote was with regards to Einsteins cosmological constant, omitted until the 1917 revision of his 1915 paper.

The author states on p117

Recent observations, as both he and Hawking mention in this book, suggest that the cosmological constant is not zero.

It is possible that there are limits to the gravitational/electromagnetic inverse squared laws that are based on standard units of measure that never exceed a constant based on Plancks constant (if the macro constant is the reciporical inverse of the micro constant, i.e. if symmetry exists)?